Rotated PSK Pilot Detection for Wi-Fi Format Identification
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current wireless local area network (WLAN) systems face challenges in efficiently transmitting data packets with varying modulation schemes, particularly in distinguishing between different formats like legacy, high throughput, very high throughput, and high efficiency wireless local area network (HEW) formats, which affects system throughput and user service quality.
Innovation Solution
A signal transmission method and apparatus that modulates pilot information using a phase-shift keying (PSK) scheme with a rotated angle, allowing the receive end to detect the corresponding data packet format by employing a binary phase-shift keying (BPSK) scheme with specific rotation angles for pilot and signaling information in the HEW format.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional modulation schemes (BPSK, QBPSK) are used for pilot information in different data packet formats, then compatibility with existing Wi-Fi standards is maintained, but the ability to accurately distinguish and detect new HEW format packets is degraded
Solution Approach 1:
The patent applies different modulation schemes to different parts of the signal: conventional BPSK/QBPSK for data payload to maintain compatibility, and rotated BPSK specifically for pilot information to enable format detection. This local differentiation allows the system to achieve both compatibility and detectability without compromising either.
Solution Approach 2:
The patent changes the 'color' (modulation characteristics) of the pilot information by applying phase rotation to distinguish HEW format packets from legacy formats. The rotated pilot symbols create a detectable signature that allows receive ends to identify HEW packets, while the data portion maintains its conventional appearance for compatibility.
2Measurement precision
If rotated BPSK modulation is applied to pilot information in HEW format packets, then accurate format detection is enabled, but complexity of the modulation and detection system increases
Solution Approach 1:
The patent changes the phase rotation parameter of the BPSK modulation for pilot symbols in HEW packets. By using a specific rotation angle (e.g., 45 degrees) that differs from conventional formats, the system creates a distinguishable characteristic without fundamentally changing the modulation architecture. The detection complexity is managed by comparing against known rotation patterns.
3Productivity
If different modulation schemes are used for different data packet formats, then spectral efficiency and system throughput are improved, but false detection rates between formats increase
Solution Approach 1:
The patent performs preliminary modulation of pilot information with a specific phase rotation before transmission. This preliminary action embeds format identification information into the signal structure, enabling the receiver to determine the packet format early in the detection process, which reduces false detections by establishing a clear distinction between formats before full signal processing occurs.
Data Source
AI summary
Embodiments provide a signal transmission method and apparatus. The method includes: modulating, by using a phase-shift keying PSK scheme with rotation of a first angle, at least a part of pilot information carried in at least one signaling symbol in a signaling field of a data packet, to obtain modulated pilot information; and sending, to a receive end, a data packet that carries the modulated pilot information. A modulation scheme different from a conventional modulation scheme is used in the embodiments to modulate pilot information carried in a signaling symbol in a signaling field of a data packet, so that a data packet format corresponding to the modulation scheme can be effectively detected at a receive end.